Method for producing citric acid

The invention provides a method for producing citric acid, which comprises the following steps: (1) treating kelp residues with an alkali solution, and separating to obtain a solid A and a clear liquid A; (2) carrying out size mixing on the solid matter A, and adjusting the pH value to weak acidity to obtain a slurry; (3) carrying out enzymolysis on the slurry; (4) sterilizing the pulp subjected to enzymolysis in the step (3); and (5) adding a strain into the slurry sterilized in the step (4), and fermenting to obtain the citric acid. The industrial waste kelp residue is fully utilized as a main raw material, and citric acid is generated through microbial treatment, so that natural resources are reasonably developed and utilized, secondary disasters caused by the natural resources are reduced, the effects of turning waste into wealth, protecting the environment and balancing ecology are achieved, and meanwhile, a new raw material is provided for producing citric acid. 本发明提供了一种生产柠檬酸的方法，包括如下步骤：(1)将海带渣用碱溶液处理，分离得